apache - Why does Jenkins complain that my reverse proxy setup is broken?

Question

I have no idea why after Jenkins is updated to version 1.591 (Ubuntu Server 12.04), the originally correctly set up reverse proxy now becomes broken. My current setting is exactly the same as said in Jenkins wiki:

ProxyPass /jenkins http://localhost:8081/jenkins nocanon
ProxyPassReverse /jenkins http://localhost:8081/jenkins
ProxyPreserveHost On
ProxyRequests Off
AllowEncodedSlashes NoDecode
<Proxy http://localhost:8081/jenkins*>
Order deny,allow
Allow from all
</Proxy>

also --prefix=/jenkins has been added into /etc/default/jenkins file

Is that a bug in Jenkins?

Answer 1

I was faced with this issue with Jenkins as a Windows Service Package.

According to their wiki:

Make sure the Jenkins URL configured in the System Configuration matches the URL you're using to access Jenkins.

To reach the System Configuration:

1. Go to your Jenkins page
2. Click Manage Jenkins
3. Click Configure System
4. Scroll to Jenkins Location and find Jenkins URL.

Ensure that port value matches with the port value set in the <arguments> section of the jenkins.xml file located in the Jenkins folder on your machine.